When a pregnant woman is exposed to low levels of a commonly used pesticide, the architecture of her developing infant's brain may be irreversibly damaged. This according to researchers who for the first time used MRI testing to see structural evidence of harm from exposure to the insecticide chlorpyrifos during fetal development.

Researchers report that the changes in brain structure they observed were consistent with the learning and developmental effects (including reduced IQs) that have been linked to chlorpyrifos. The effects were observed at exposure levels well below those considered harmful by EPA.

For more than 50 years, Dow Chemical Company and Shell Oil knowingly included a highly toxic waste chemical in their fumigant pesticide products, rather than paying to dispose of it properly. The chemical, 1,2,3-trichloropropane (TCP), is a known carcinogen.

TCP is considered a "garbage" chemical because it is a by-product of the plastics manufacturing process — it is not intentionally produced. By including TCP in their fumigants, which are widely used in California to kill nematodes, Dow and Shell Oil contaminated drinking water in communities throughout the San Joaquin Valley. Several cities are now suing both companies for cleanup costs.

If we set our minds to it, we can turn back the rising tide of autism. But it will take the courage to embrace the following common-sense goal, in both policy and practice: Expecting parents and young children should not take in chemical contaminants that are known to harm developing minds.

This week, scientists released a list of exactly which contaminants we're talking about. The top 10 chemicals contributing to autism and learning disabilities include commonly used pesticides, as well as chemicals found in many consumer products. The scientists tell us the list is likely to grow. But for now, it's time to act on what we know.

Today, on April 25th, we celebrate World Malaria Day. It’s an opportunity to reflect on a serious disease that still affects far too many of the world’s poor. For Africans like myself, it is also an opportunity to highlight an on-the-ground perspective of how best to control malaria.

We've seen that the most effective strategies don't rely on chemical solutions, but on a comprehensive set of tools like biological control of disease vectors, environmental management, individual protections and public health education.

Last week was a busy one for Sofía Gatica. On Monday, she won the global Goldman Environmental Prize for her efforts to protect her children and neighbors from pesticides. On Wednesday, she asked President Obama to investigate Monsanto’s “pesticide poisonings and livelihood harms” in her community and beyond.

It makes perfect sense. After all, both the genetically engineered soy beans that now surround her small Argentine community — and the herbicide those beans are designed to withstand — were produced and aggressively marketed by a company based right here in the U.S. In St. Louis, Missouri, to be precise.